Is it possible to consider having coliseum events to have a 24h time frame? Not everyone can play this at that timing. Plus there is a match limit imposed so it wouldnt affect anyone negatively, would it?

30 fights per player seems so wrong on so many levels !!!! this is what i hate about a fight limit, after more than half the players that participate finish their 30 fights then come the real good players and bump everyone down 200-300 spots ... in one event i was in the top 500 and i thought i was safe for the 10 credits prize, but i was bumped off my spot by 200-300 spots by players that waited till much later to join in the event, thats why there shoud be just a time limit on Coliseum events not a fight limit !!!

Simple. Spread out your play time if you think that you're at a disadvantage by playing first. But dont forget the more number of people out there that will be playing as well. Not all of them could be very good players. 12 hours is also not a bad move. 6 hours is just too short for 30 matches.

It doesn't make much difference how late a player joins. If he or she performs well, they will secure a top spot regardless of when they join. They have no other influence on your score. All you can do is play your best with your fight limit.